POLYCYCLIC AROMATIC HYDROCARBONS (PAHS) IN AMAZONIAN AQUATIC ENVIRONMENTS: IMPLICATIONS FOR THE CONSERVATION OF FRESHWATER STINGRAYS

The River Negro is an ecologically important Amazonian river characterized by unique physicochemical conditions, high biodiversity, and increasing anthropogenic pressures. Among the contaminants of concern in this environment are polycyclic aromatic hydrocarbons (PAHs), which originate mainly from petroleum-related activities and incomplete combustion processes. Because of their persistence, hydrophobicity, and affinity for organic matter, PAHs tend to accumulate in sediments, where they may become sources of exposure for aquatic organisms. Freshwater stingrays of the subfamily Potamotrygoninae are particularly relevant in this context because of their benthic habits, close interaction with sediments, trophic position, and biological characteristics that may increase their vulnerability to environmental disturbances. Although PAH contamination has been reported in Amazonian environments, studies on these contaminants in freshwater stingrays remain scarce. Therefore, investigating PAH occurrence, distribution, environmental transfer, and potential biological effects is essential to support aquatic ecosystem monitoring, stingray conservation, and sustainable management of Amazonian resources.